Today's limited coal and extinguishing fuel resources have led to a greater need for exploiting renewable energy resources. Tidal energy, wave energy, water power or similar forms of mechanical energy of a fluid system are few of the alternative renewable energy resources that can be used.
Despite numerous advantages offered by mechanical energy of a fluid system, the systems used therein have various problems including                a) causing damage to the environment including fish and plant damage or migration,        b) deposits such as silt or mud, on the machines used in such system,        c) blockages caused in the machines used due to waste and sewage        d) damage occurring to machines or their parts due to water flow.        
Over the years, barrages or dams have been adapted typically to convert this energy into electricity by forcing the water through turbines and activating a generator. However, since such barrages and dam systems are rare and man-made, huge capital and maintenance is required to operate them, and the rare availability of such sites leads to escalation of expenditure. There may also be losses due to long transmission of power in such systems.
It is well known that water sources such as oceans, sea, rivers, lakes, creeks, ponds, canals and others are naturally available in abundant and are wide spread. However, comparative to dams (fams) and barrages there are limited systems in the art which can be used effectively for such water sources, and more so in low flow rate currents as well as high flow rate currents, and thereby leading to less effective and sporadic generation of power.
In another aspect of the background of this invention, it is observed that systems involving use of turbine for utilizing mechanical energy of a fluid system to generate power is a common practice as seen in the art. However, the design and working of said most of the know methods in the art fail to overcome the above mentioned problems.
In another aspect of the background of this invention, it has been also observed that the velocity of upper layers of flowing water is high as compared to lower layers. Velocity gradient is present in flow of the water, which further limits the vertical length of turbine thus may reduces the efficiency of the turbine. So there is need to construct vertical axis turbines in accordance with velocity gradient, for better efficiency of the turbine.
Attempts have been made to overcome the above mentioned problems, wherein a piston-like or similar arrangement is used to compress the air and such compressed air is used for power generation. However, in comparison to turbine based systems these systems may have several shortcomings such as:                a) pistons may be comparatively more costly,        b) mechanical parts of the piston are prone to wear and tear,        c) maintenance costs may be high, and        d) may not be used where the water flow rate is substantially low.        
The present invention provides alternative to similar systems and methods in the art and also may be cost effective and efficient. In its various embodiments, present invention also addresses the above mentioned and other possible drawbacks and limitations of the currently used systems and methods relating to the field of velocity gradient floating turbine and the power generation system and methods thereof.